Large manipulators are known in a multiplicity of embodiments from the prior art. A large manipulator with an articulated mast is disclosed for example by WO 2014/166637 A1.
As pivoting drives which are used for pivoting the mast arms about the articulated joints relative to the respectively adjacent mast arm or mast pedestal, use is typically made of hydraulic cylinders. These are actuated, by means of proportionally operating actuation valves, by an electronic control device for the purposes of making it possible to variably predefine the movement speed of the individual hydraulic cylinders. In the case of known large manipulators, the movement speed of the individual hydraulic cylinders is normally limited, because an excessively fast movement of the articulated mast poses a hazard to persons situated in the surroundings. To ensure operational safety, there are legal standards which specify the admissible maximum speed of the tip of the articulated mast.
In the prior art, the control valves of the hydraulic cylinders are actuated by means of a remote controller which is connected (wirelessly or by wires) to the control device. Alternatively, the control valves may (for example in an emergency mode) be controlled manually using hand levers. The control valves are in this case designed such that a particular position of an operating lever on the remote controller corresponds to a defined volume flow of the hydraulic fluid, that is to say a defined movement speed of the respective hydraulic cylinder, specifically regardless of the pressure conditions respectively prevailing in the hydraulic system. Here, the control valves are designed such that, when all joints are pivoted simultaneously with the maximum movement speed and the articulated masters in the fully straightened state, the permitted maximum speed of the mast tip is not reached. This design of the control valves has the disadvantage that the legally permitted scope for the movement speed of the mast tip is, in most practical cases, very poorly utilized. The above-discussed “worst case”, in which all of the joints are moved with the maximum speed in the case of a fully straightened articulated mast, practically never occurs. The limitation of the movement speed therefore leads, in most cases, to a very slow mast movement. As a result, considerable time delays arise during the folding-out and folding-in of the articulated mast. This makes the operation thereof inefficient.
The abovementioned WO 2014/16637 A1 proposes a large manipulator in the case of which the control device provides a rapid traverse facility for the rotary drive of the mast pedestal in order to rotate the articulated mast into the desired working position with increased speed, wherein the rapid traverse facility can be selected only when the mast or jib is in the fully folded-together state. A single sensor which interacts with the control device is provided in the known large manipulator, wherein, by means of the sensor, it can be detected whether or not the articulated mast is in the fully folded-together state. The sensor outputs an enable signal to the control device as long as it is ensure that the articulated mast is folded together and thus has a minimum radius. In the state, the articulated mast can be rotated at increased speed.